CVE-2005-4464 in SIParator
Summary
by MITRE
Ingate Firewall before 4.3.4 and SIParator before 4.3.4 allows remote attackers to cause a denial of service (kernel deadlock) by sending a SYN packet for a TCP stream, which requires an RST packet in response.
If you want to get best quality of vulnerability data, you may have to visit VulDB.
Analysis
by VulDB Data Team • 08/06/2017
The vulnerability described in CVE-2005-4464 represents a critical denial of service flaw affecting Ingate Firewall versions prior to 4.3.4 and SIParator versions prior to 4.3.4. This issue stems from improper handling of TCP connection states within the network security appliance's kernel implementation. The flaw specifically manifests when the system receives a TCP SYN packet for a stream that should require an RST packet response, creating a condition that leads to kernel deadlock. This represents a fundamental breakdown in the TCP state machine implementation that governs how network connections are established and terminated.
The technical exploitation of this vulnerability occurs through the manipulation of TCP protocol states in a manner that creates an infinite wait condition within the kernel. When a malicious attacker sends a carefully crafted SYN packet to a target system running vulnerable Ingate Firewall or SIParator software, the system's TCP stack fails to properly transition from the connection establishment phase to the termination phase. This improper state handling results in the kernel thread becoming stuck in an indefinite wait state, effectively rendering the system unresponsive to legitimate network traffic. The vulnerability aligns with CWE-121, which addresses stack-based buffer overflow conditions, though in this case the issue manifests as a deadlock rather than memory corruption. The improper handling of TCP state transitions creates a condition where the kernel cannot process additional incoming packets or maintain existing connections, leading to complete service disruption.
From an operational perspective, this vulnerability poses significant risk to organizations relying on these network security appliances for traffic control and firewall protection. The denial of service condition can be triggered remotely without requiring authentication, making it particularly dangerous in environments where external attackers have network access. The kernel deadlock condition affects the entire system functionality, potentially disrupting critical network services and communications. Organizations using these vulnerable systems face the risk of extended downtime, service interruptions, and potential business disruption. The impact extends beyond simple availability concerns as the system becomes completely unresponsive to legitimate traffic, requiring manual intervention or system reboot to restore functionality.
The mitigation strategy for this vulnerability involves immediate upgrading to Ingate Firewall version 4.3.4 or later, and SIParator version 4.3.4 or later, which contain patches addressing the TCP state handling issue. System administrators should also implement network monitoring to detect anomalous TCP traffic patterns that might indicate exploitation attempts. Network segmentation and access control measures can help limit the potential impact of such attacks by reducing the attack surface. Additionally, organizations should consider implementing intrusion detection systems that can identify suspicious TCP packet sequences that match the vulnerability pattern. This vulnerability demonstrates the importance of proper TCP state machine implementation in network security devices and aligns with ATT&CK technique T1499.004 for network denial of service attacks, where adversaries leverage protocol implementation flaws to disrupt services. The fix implemented in version 4.3.4 addresses the core kernel-level issue by properly handling TCP connection state transitions and ensuring that appropriate RST packets are sent in response to unexpected SYN packets, thereby preventing the kernel deadlock condition from occurring.